<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

        * {
            padding: 0;
            margin: 0;
        }

        .wrapper {
            width: 400px;
            height: 200px;
            border: 1px solid black;
            display: flex;

        }

        .content {
            flex: 1 1 auto;
            /* 设置几个子元素，让其等分剩余空间 */
            margin: 0 5px;
            border: 1px solid green;
            height: 100px;
            box-sizing: border-box;

        }





    </style>
</head>
<body>
    <div class="wrapper">
        <div class="content"></div>
        <div class="content"></div>
        <div class="content"></div>
        <div class="content"></div>
    </div>
</body>
</html>